This invention relates to an apparatus for evening the fiber lap supplied to the input of a carding machine, a roller card unit, a cleaner or a similar fiber processing machine. The fiber lap is obtained from a fiber tuft feeder (such as a feed chute) which is associated with the fiber processing machine and in which the fiber distribution over the width of the fiber lap discharged by the feed chute is measured and the signals representing the measured values are utilized to automatically regulate the air flow in the feed chute along the width thereof to thus regulate the distribution of material along the feed chute width.
In a known apparatus of the above-outlined type, a significant space is present between the lower end (discharge end) of the feed chute and the downstream-arranged fiber processing machine, such as a card or a roller card unit. The fiber lap which is downwardly withdrawn from the feed chute is fed to the feed roller of the fiber processing machine on a transfer tray. The measuring of the material distribution along the width of the fiber lap is effected by sensing the thickness of the throughgoing material by means of "pedals" arranged parallel to the width of the fiber lap. The setting member is an adjustable air outlet opening which extends along the width of the feed chute and which is divided into adjustable sections, whereby the air outlet passage may be increased or reduced. Because of the distance between the measuring member and the setting member there results an undesired delay of the regulation of the fiber lap, particularly as concerns thickness fluctuations.